Seepage Control in Sand Using Bio-Gelation Method

Seepage control is a key concern for excavation or other types of underground construction. Although several methods have been adopted including chemical grouting, we still need methods that can reduce the permeability of sand and control seepage in a quicker and more cost-effective way. One of the potentials is gelation method. By introducing alginate solution underground in sand layer and producing calcium ion underground at the same time, hydrogel can be formed to occupy the pores in sand. In this way, the permeability of sand can be much reduced to achieve the seepage control purpose. In this paper, some experimental results on the hydrogel formation procedures and permeability reduction effect are presented. A small-scale model test was also conducted, and the results of this model tests are given as well. This study has shown that gelation can be an effective and yet inexpensive method for seepage control, which can drastically reduce the permeability of sand from the magnitude of 10^-4 to 10^-7 m/s. However, this method suffers from other limitations too such as durability. The advantages and disadvantages of the proposed method are discussed as well.